A variety of different devices have been used to retract delicate tissue during surgical procedures. One such device is illustrated in United States Patent Publication Number 2010/0010315, which is incorporated herein by reference. FIG. 1 of this publication illustrates a soft tissue retractor system having a hollow retractor 100, and an introducer 102 that is selectively inserted into the retractor 100. The retractor 100 and/or introducer 102 may include a handle 104 to facilitate manipulation and placement of the retractor system, and a lock to hold the introducer and retractor together. The handle 104 is configured to connect to a clamp 106, such as the standard surgical clamp 106 shown in FIG. 1. The device in FIG. 1 (with some modifications) is commercially sold as the “VBAS” device by Vycor Medical, Inc. of Boca Raton, Fla.
A retractor system such as shown in FIG. 1 is often used by inserting the introducer 102 into the retractor 100 and locking it in place, so the two can be moved and manipulated as a unit. The combined retractor system is inserted into the patient's body and moved to the surgery site, and then the introducer 102 is unlocked and removed to permit access to the site through the retractor 100. When the unit is in place (either before or after the introducer 102 is removed), the handle 104 may be locked to a clamp 106 to hold the retractor 100 in place. Surgeons using this retractor sometimes do not use a clamp to hold the retractor at the surgery site, and often manually manipulate the retractor to access different parts of the surgery site during the surgical procedure. The retractor system and the retractor may be manipulated by holding the proximal ends of the introducer or retractor or by holding the handle.
The device shown in FIG. 1 may have a transparent introducer 102 and/or retractor 100, and surgeons using such devices advantageously use the transparent introducer and retractor to observe the underlying tissue and to visually guide the unit to the surgery site. While it has been found that visual guidance by looking through the introducer 102 is very beneficial, it also has been found that some form of additional guidance or navigation may be desired in some cases. For example, in some cases, surgeons have used a probe or guide wire (a narrow elongated rod) to guide the movement of the retractor system. In such cases, the probe is advanced to the surgery site, and then the interlocked retractor system is slid over the probe until it reaches the surgery site. This is facilitated by the inclusion of a hole at the tip of the introducer that fits around the probe. If the hole through the tip of the introducer is absent, this method cannot be used. This type of system is described in United States Patent Publication Numbers 2008/0109026 and 2009/0048622, which are incorporated herein by reference. These references also show an alternative construction, in which the retractor is not locked to the introducer.
It has been found that some surgeons using the above procedure may use a probe that is integrated into a computer navigation system. For example, the probe may include a so-called “starburst” or the like, on the probe's proximal end (i.e., the end opposite the distal end that is inserted to the surgical site). This and other navigation systems are known in the art. For example, frameless navigation systems and other computerized guidance systems and methods are described in U.S. Publication No. 2001/0027271 (which is incorporated herein by reference in its entirety) and others, and are commercially available from companies such as Medtronic, Inc., Stryker, BrainLab, AG, and GE Healthcare. As used herein, “computerized guidance” encompasses any method of guiding a device to or at a surgical site that relies on computer visualization and/or control.
United States Patent Publication Number 2010/0010315 briefly notes the possibility of using stereotactic guidance or navigation in conjunction with a surgical retractor, but does not illustrate or describe this procedure or any apparatus for accomplishing this objective. Nevertheless, surgeons have been known to use a navigation probe “freehand” with a VBAS device such as shown in FIG. 1. In such cases, the surgeon holds the navigation probe in place within the introducer while advancing the unit towards the surgery site. The tip of the probe may be placed in or near an opening through the tip of the introducer, but the opening through the introducer may be somewhat larger than the probe tip and is oval, and does not hold the probe tip in any particular orientation. Such techniques can suffer from inaccuracy and displacement of the probe from the introducer tip, and it can be difficult to hold the probe in place. Also, in some cases the probe tip may extend partially through the introducer tip opening, which can risk damaging underlying tissue. However, freehand use can be helpful to allow occasional removal of the probe to provide an unobstructed view through the introducer of the underlying tissue.
While computerized surgical guidance systems are well-known, a number of limitations exist with respect to their use with retractor systems, and particularly with systems like those shown in FIG. 1. For example, while some surgeons use computerized guidance to direct a probe to the surgery site, and then slide the retractor system over the probe to the site, the movement of the retractor may be somewhat imprecise and the process can be unduly cumbersome. This method also is not available if the retractor system does not have a through-hole that fits over the probe (due either to the absence of a hole or a hole that is too small). In addition, the probe does not provide a view of the tissue through which it is advanced, so there is no visual means to perceive and avoid critical tissue (e.g., major blood vessels or nerves) when inserting a probe before inserting a retractor/introducer system. Also, the small-diameter probe may sever delicate tissue cells, such as grey or white brain matter, rather than moving the cells aside and passing between them as would be expected to happen when advancing the retractor system.
United States Patent Publication Number 2013/0066154, which is incorporated herein by reference, shows examples of systems for integrating a navigation probe into a surgical introducer. For example, FIGS. 1-6 of this publication show a navigation probe that is secured to the inside of a pre-existing introducer by resilient means, such as rubber plugs or O-rings. Another embodiment uses a slip fit (e.g., FIGS. 7-8), and still another embodiment uses an arm to hold the probe down inside the introducer (FIG. 9). Still other versions mount the navigation device outside the introducer, to an arm that is connected to the retractor assembly (FIGS. 10-11). While these systems may provide suitable performance, they also have certain potential shortcomings. For example, resilient plugs may slip in the presence of fluids and may be difficulty to disengaged to remove the navigation device during surgery, a slip fit requires careful monitoring to ensure proper positioning, an arm as shown in FIG. 9 to hold the probe in place requires the probe to be modified to include a surface against which the arm pushes, and locating the navigation device outside the introducer complicates the correlation between the navigation device and the tip of the introducer or retractor.
United States Patent Publication Number 2012/0071748, which is incorporated herein by reference, shows another example of a system for integrating a navigation probe into a surgical introducer. In this case, the probe is retained in a narrow channel through the introducer, and held in place with a threaded locking screw. The locking screw adds an additional potentially-removable part to the operating theater, and therefore this reference adds a separate retaining device (see FIG. 7B) to prevent the locking screw from being removed. The locking screw also can be relatively difficult to manipulate, particularly when wearing surgical gloves.
United States Patent Publication Number 2016/0015374, which is incorporated herein by reference, shows yet another example of a system for integrating a navigation probe into a surgical introducer. The device shown in this publication holds the probe in a tube-like sheath that extends distally into the introducer from the proximal open end of the introducer, and has a convenient single-throw clamp to lock the probe in place. This device also optionally includes a mechanism to indicate when the navigation probe is fully seated in the introducer. While this device is useful to ensure greater accuracy and registration between the introducer and the navigation probe, it may obstruct the surgeon's view to some degree, and may make frequent removal and reinstallation of the navigation probe somewhat cumbersome as compared to freehand use of the probe.
It has been found that there still remains a need to provide alternative apparatus and methods for coordinating the use of guidance systems with surgical introducers.